The left recurrent laryngeal nerve loops under which structure?

• A. Aortic Arch
• B. Subclavian Artery
• C. Carotid Sinus
• D. Pulmonary Artery

Answer: (A)

The left recurrent laryngeal nerve has its distinctive path in the mediastinum: after branching from the vagus, it travels downward and then loops upward around a major vessel in the arch area. It specifically loops under the arch of the aorta, just near the ligamentum arteriosum, before ascending in the tracheoesophageal groove to reach the larynx. This is why the left nerve is described as looping under the aortic arch. By contrast, the right recurrent laryngeal nerve loops under the right subclavian artery. The other structures listed aren’t the vessels that form the loop for the left nerve.